Scroll saws are widely used by amateur and professional woodworkers and are particularly useful for cutting decorative 2-dimensional figures from wood using an elongate scroll saw blade which makes small and curvateous cuts. Current scroll saw models utilize a variety of parallel arms forming C-shapes pivoting to provide vertically aligned movement of thin saw blades suspended between the ends of the arms. To cut out a section within a workpiece a hole is first drilled in the wood within a portion of the wood the blade will cut out, and the blade inserted and mounted on the scroll saw to begin the cutout. Many operators of scroll saws use small blades which provide relatively smooth cuts through wood that do not require further finishing. In many cases the operators conclude that no further finishing is required mainly because no quick and easy method for finishing and controlling the finishing has been previously available. Other users find that burn marks, rough cut edges, and other imperfections require considerable further and laborious hand finishing. These finishing requirements are especially prevalent with low cost scroll saws using pin-end blades, and are many times desired by high-end, more costly pin-less and pin-end scroll saw users. In the cutting of the intricate designs, a great deal of time is required to fasten and unfasten scroll saw blades, and consequently a rapid method of inserting and mounting a finishing tool, or abrasive, on a scroll saw is required. Unfortunately, there has been no equivalent scroll saw abrading system which is as quickly fastened and unfastened as scroll saw blades. The subject invention embodiments address these issues.
There are, commercially available, a variety of reciprocating small hand and electric oscillating and sanding tools and saws that make use of a replaceable sanding, abrading, or cutting elements such as sandpaper sheets and sandpaper belts. Some hand and mechanical sanders are comprised of clamps which secure the ends of a piece of an abrasive firmly supported against a backing. These tools range from hand held blocks to reciprocating or orbiting sanding surfaces at high speeds. Most tools are not ordinarily useful for small delicate sanding, sanding of small and unusually-shaped work pieces, or delicate sanding of very complicated internal small and narrow spaced areas. The embodiments of this invention provide a tool to facilitate work and provide better quality of sanding finishes. The advent of advanced techniques of support and belt design, durability, materials, and manufacture of the support has allowed these embodiments to take advantage of new technologies and materials. The abrading materials attached to belts, bands, strips, meshes, and abrasive members have been manufactured with metal, cloth, or other reinforced backing materials, with cutting surfaces comprised of particulate materials such as steel, metals, carbides, borides, nitrides, silicates, tungsten, or equivalent diamond substitute materials fused or adhered to the surface. These abrasive particles provide a multiplicity of cutting edges of size and shape. The backings provide substantial tensile strength which thereby increases the strength and durability of the sandpaper and permits its use without conventional support that sandpaper ordinarily requires when used without such backing.
U.S. Pat. No. 4,977,712 by Fisher, et. al., details a hand sander with abrasive member belt. The system offers a hand sander with a very narrow jaw depth. The system uses a complicated tensioning mechanism. The instrument must be purchased separately and is not an accessory tool or item. The abrasive strip cannot be mounted evenly to provide even tension using the tapered pegs, holes and recesses.
U.S. Pat. No. 3,874,126 by Catlin, et. al. details a flexible abrading tool utilizing a specially made metal or grit impregnated band with a rigid backing. The system cannot be applied to a scroll saw. The system provides limited control and narrow jaw depth for use due to the hand held saw construction, limited tensioning, and cannot be carefully controlled with respect to band angles and depth. The tool does not leave the operator's hands free for precise manipulation of workpiece movement. The abrading tool is expensive to manufacture, replace, and is not disposable. The hardened steel structure produces grooves on materials and cannot contour to surfaces. The blade mounts only in hand held narrow C-shaped saws, and the brackets can only clamp and hold the abrasive blade if the blade is made of metal. The tool is specifically built and comparatively expensive.
U.S. Pat. No. 4,802,310 by Holmes details an elastic backing to hold an inelastic abrasive sheet which delaminates easily from the adhering surface junction. The contact adhesive cannot withstand the multiple releasing and re-adhering processes. The jaw depth is limited and the elastic cannot provide controlled pressure of the abrasive sheet to the working surface. Uniform band tensioning is difficult to control.
A number of scroll saw clamps for holding pin and plain pin-less end scroll saw blades have been designed to facilitate use and rapid replacement of various saw blades. In general, a sabre saw can be designated as a power tool where one end of a saw blade is fixed in a mounting. A reciprocating saw can be designated as a tool where two symmetrically disposed ends are fixed in a mounting. A scroll saw is a power tool whereby the reciprocating action is augmented by a power tool motor component. Representative scroll saw blade holders are found in U.S. Pat. Nos. 5,351,590 by Evert, et. al., 5,272,948 by Theising, 5,105,704 by Chang, 5,058,280 by Pollak, 5,016,512 by Huang, 4,953,431 by Chen, 4,841,823 by Brundage, and 4,838,138 by Rice, et. al., 4,807,507 by Rice, et. al., and 4,670,986 by Chen. All have small narrow clamping surfaces as a necessary requirement for the suspension of the blade in reciprocating saw. All address the pivoting movement required to maintain the movement of the blade for a straight vertical cut. All scroll saw clamp designs have the pivot point parallel to the oscillating axis of the scroll saw and allow the blades to be mounted in one orientation as a necessary and sufficient requirement of all designs. All clamps securing pin-less scroll saw blades have surfaces, screws or clamps which hold the narrow saw blades using screws and levers to increase surface clamping pressure and facilitate rapid interchangeability. These clamps also address orientation of scroll saw blades, for example at 0, 90, 180, and 270 degrees. The tensioning of a mounted blade is performed by a screw or lever which increases the spacing between the ends of the scroll saw arms. For pin-end blades, and other pin-less blade holders, the mounting brackets do not clamp the pin-end in place, rather the pins of the saw blades rest in recesses, or grooves on a mounting plate or arm, which provide the pivot point and exact placement of the blade in the scroll saw.
U.S. Pat. No. 3,914,906 by Barnes details a sanding member for a reciprocating saw. The sanding or abrading blade on the sabre saw cannot be viewed by the user during operation to determine the extent of sanding and removal of ridges and contour lines. The blades are flexible and cannot provide even pressure longitudinally in the direction of blade motion. The adhesive sheet is difficult to replace and can delaminate from the rigid support backing. The rigid support member is thick and cannot contour to narrow radiused convex and concave surfaces. In such a capacity it generates, rather than eliminates, sanding grooves. When symmetrically supported the system cannot sand surfaces of small radii. The metal band support cannot curve and delaminates from the abrasive sheet. The adhesive holding the abrasive sheet to the metal support backing must be removed completely from the support for adhesive sheet material replacement, and these abrasive sheets must be cut individually. The individuality of each support, and cutting of each abrasive sheet, as well as difficulties in applying the abrasive sheet in the correct alignment and orientation, create significant difficulties with use and replacement. Any adhesive material used to affix the old sandpaper to the metal backing which remains on the rigid back support member prior to application of a new abrasive sheet over these areas can cause rises and flaws on the abrasive surface and is subsequently expressed as damage on the workpiece. The system is not disposable, not easily interchanged for various grit sizes without removing the abrasive sheet, and hence not convenient to operate. This limits rapid interchangeability of sanding surfaces. The Barnes system as presented cannot be mounted in place in many of the current manufactured scroll saw mounting systems.
U.S. Pat. No. 4,841,823 by Brundage details a scroll saw blade holder and positioner permitting adjustment of the saw blade relative to the pivot beams, or arms, of the scroll saw such that the plane movement of the blade is coincident with the blade directly, particularly in the event that the ends of the arms are somewhat misaligned with respect to the plane of travel of the arms due to inaccuracies of the arm pivot beam locations and cutting stress bending loads of the blade during operation. The holder and associated mounting components are expensive to manufacture as well as complex to assemble and align.
U.S. Pat. No. 4,707,947 by Harris details a system using a hard stone over an abrasive element adhered to a surface blade for a sabre saw. The disadvantages of the hard stone member are similar to those found in U.S. Pat. No. 3,914,906.
U.S. Pat. No. 4,953,431 by Chen details a plain pin-less scroll saw blade holder, saw blade suspension device for clamping of small commerically available pin-less scroll saw blades. The fine pin-less blade is inserted in a 1/8" diameter hole and clamped between two set screws. The small diameter hole for the blade accepts only pin-less metal scroll saw blades. The device provides a very complex to assemble, awkward to handle and use, pin-less blade holder which is costly to manufacture. The holder clamps only metal blades and not flexible, softer materials, thus cannot hold onto an abrasive member without damaging the support material.
U.S. Pat. No. 4,670,986 by Chen represents a method for clamping a pin-less saw blade whereby the holder provides the pivot point for the blade on the arm of a scroll saw. The system requires that the saw blade be released prior to and after inserting in a small hole for cutting. A number of additional tools or fastening assistance devices are required to provide sufficient clamping force to suspend the blade. The clamping surface area is small and narrow, yet sufficient to clamp the blade without blade end distortion.
U.S. Pat. No. 4,838,138 by Rice, et. al., details a pin-less blade holder and aligning device for a scroll saw. Like U.S. Pat. Nos. 4,953,431, 4,807,507 and 4,670,986 the holders require separate tools for blade installation and alignment for clamping only thin and arrow pin-less blades.
U.S. Pat. No. 5,351,590 by Everts, et. al., details a pin-less scroll saw blade holder, saw blade suspension device for clamping of small commercially available pin-less scroll saw blades. The holder provides a clamping force on a plain pin-less scroll saw blade through a pair of jaws by way of a thumbscrew and actuator. The depth of the blade is limited, allowing only pin-less blades to be clamped. The holder cannot turn 90 degrees for an alternative cutting direction.
U.S. Pat. No. 5,058,280 by Pollak details a pin and pin-less scroll saw blade holder nearly identical to U.S. Pat. No. 4,953,431 with the added feature of a sliding metal plate which inserts between the pin-less blade and the commonly incorporated clamping screws. The function of the plate is to allow a slightly increase clamping area for the blade and prevent distortion of the blade end. While providing somewhat increased surface area the holder accepts only narrow blades, cannot hold varied cross-sectional area pieces, cannot hold wide strips uniformly, is bulky and comprised of several individual pieces, and is not disposeable. The blade and mount cannot be rotated.
Flexifile, by Creations Unlimited Hobby Products, Dept P, Grand Rapid, Mich. 49505, offers the user a symmetrically disposed, two loop, narrow and fine abrasive member supported by two pins at the ends of a handheld C-shaped holder. In such a configuration, the C-shaped holder does not allow adjustable tensioning, operation allows only one hand free for control, and provides only narrow fine abrasives. The depth of the holder is limited to approximately 4 inches, which limits application use. The system is very small and cannot be adapted to a scroll saw. The system does not allow the user to carefully guide the work. The abrasive member is very weak, and cannot be used on large wooden pieces.